A semimathematical model for library circulation control. The application is intended to contribute to a more structured yet flexible approach to library circulation management. It includes provisions for circulation policy analysis and management, recording, and controlling of circulation transactions. (Author/KP)

Principal component analysis, image component analysis, and maximum likelihood factor analysis were compared to assess the effects of variable sampling. Results with respect to degree of saturation and average number of variables per factor were clear and dramatic. Differential effects on boundary cases and nonconvergence problems were also found.…

An algorithm for assessing the correspondence of one or more attribute rating variables to a symmetric matrix of dissimilarities is presented. It is useful as an alternative to fitting property variables into a multidimensional scaling space. The relation between the matrix and the variables is determined by evaluating pairs of pairs relations.…

The purpose of this study was to demonstrate a potential difficulty with relying on null models in LISREL confirmatory factor analytic measurement models and to offer several suggestions for dealing with this concern. Using randomly generated factors in a matrix of 46 aptitude tests, it was shown that this approach is unlikely to reject even…

This package contains four FORTRAN 77 programs for Markov Model based learning experiments. One program estimates the likelihood of a one-stage learning model, another delivers estimates for a two-stage learning model. The third and fourth were designed for hypothesis testing the parameter differences between and within experimental conditions,…

Presents Price's law, which states that half of the literature on a subject will be contributed by the square root of total number of authors publishing in that area, and assesses it against empirical evidence and simulated productivity distributions. The discussion covers this law's relation to Lotka's law and its empirical validity. (Author/CLB)

Supporting the use of separate analyses of measurement and structural portions of latent or mixed manifest and latent variable models, limited information (single equation) procedures are presented for estimating structural parameters. These procedures are recommended for testing specific causal hypotheses and locating specific structural model…

A FORTRAN 77 program is described that computes both the different response success-error patterns and their summary statistics for learning and forgetting in fixed trial experiments using a two-stage Markov model. (Author/GDC)

A complete package for Markov model-based fixed trial learning experiments contains four FORTRAN 77 programs. Two of the programs deliver likelihood and parameter estimates of one- and two-stage learning models, and two may be used for hypothesis testing of parameter differences between and within experimental conditions. (Author/GDC)

Equivalence of marginal likelihood of the two-parameter normal ogive model in item response theory and factor analysis of dichotomized variables was formally proved. Ordered and unordered categorical data and paired comparisons data were discussed, and a taxonomy of data for the models was suggested. (Author/GDC)

A general latent variable model allows for maximum likelihood estimation with missing data. LISREL and LISCOMP programs may be used to carry out this estimation. Simulated data were generated. The proposed Full, Quasi-Likelihood estimator was found to be superior to listwise present quasi-likelihood and pairwise present approaches. (Author/GDC)

The use of semiparametric models may require incorporating additional functions which do not vary across distributions and may require expressing the models in terms of the joint distribution of response class and response time. (Author/LMO)

A common functional relationship among Lotka's law, Bradford's law, and Zipf's law is derived. The proof takes explicit account of the sequences of observed values of the variables by means of an index. This approach results in a more realistic and precise formulation of each law. (Author/EM)

The derivation of a general retrieval effectiveness measure is investigated. Inconsistencies in the definition of relative importance are resolved, and it is shown that the influence of the assigned weight on the effectiveness measure can produce counterintuitive results. An alternative effectiveness measure provided by the Marczewski-Steinhaus…

A description of a Mokken test program to test the robustness of nonparametric Stochastic scales is presented. For each sample and the whole population, different scale statistics (both on scale and on item level) are computed recursively. A statistic T is presented for testing the robustness of the scales in the samples. (Author)